[pygobject] Fix crash when returning (False, None) from Gtk.TreeModel.do_get_iter()

[Martin Pitt <martinpitt src gnome org>]

commit 8f31e85db1392eb7222593fc0d05144c2bca06a3
Author: Simon Feltman <s feltman gmail com>
Date:   Sun Jul 29 23:36:25 2012 -0700

    Fix crash when returning (False, None) from Gtk.TreeModel.do_get_iter()
    
    Add a Py_None check before attempting memcpy().
    
    https://bugzilla.gnome.org/show_bug.cgi?id=680812
    
    Signed-off-by: Martin Pitt <martinpitt gnome org>

 gi/pygi-closure.c       |   10 +++++++---
 tests/test_overrides.py |    9 +++++++++
 2 files changed, 16 insertions(+), 3 deletions(-)
---
diff --git a/gi/pygi-closure.c b/gi/pygi-closure.c
index 8c8e13d..b05f2d1 100644
--- a/gi/pygi-closure.c
+++ b/gi/pygi-closure.c
@@ -81,9 +81,13 @@ _pygi_closure_assign_pyobj_to_out_argument (gpointer out_arg, PyObject *object,
            interface_type = g_base_info_get_type (interface);
 
            if (!g_type_info_is_pointer (type_info) &&
-	       interface_type == GI_INFO_TYPE_STRUCT) {
-               gsize item_size = _pygi_g_type_info_size (type_info);
-               memcpy (out_arg, arg.v_pointer, item_size);
+               interface_type == GI_INFO_TYPE_STRUCT) {
+               if (object == Py_None) {
+                   arg.v_pointer = NULL;
+               } else {
+                   gsize item_size = _pygi_g_type_info_size (type_info);
+                   memcpy (out_arg, arg.v_pointer, item_size);
+               }
                break;
            }
         }
diff --git a/tests/test_overrides.py b/tests/test_overrides.py
index 3d25d52..2aa803a 100644
--- a/tests/test_overrides.py
+++ b/tests/test_overrides.py
@@ -1570,6 +1570,15 @@ class TestGtk(unittest.TestCase):
         self.assertRaises(IndexError, tree_store.__delitem__, -101)
         self.assertRaises(IndexError, tree_store.__delitem__, 101)
 
+    def test_tree_model_get_iter_fail(self):
+        # TreeModel class with a failing get_iter()
+        class MyTreeModel(GObject.GObject, Gtk.TreeModel):
+            def do_get_iter(self, iter):
+                return (False, None)
+
+        tm = MyTreeModel()
+        self.assertEqual(tm.get_iter_first(), None)
+
     def test_tree_model_edit(self):
         model = Gtk.ListStore(int, str, float)
         model.append([1, "one", -0.1])